Electromagnet



May 8,1928.

' A. E. ANDERSON ELECTROMAGNET Filed April 23, 1925 Patented May 8, 1928.

UNITED STATES PArENr-oF icE;

ALF E. ANDERSON, OF -MILTON, MASSACHUSETTS, ASSIGNOR TO ALBERT & J'TM. Ail- 'DERSON MANUFACTURING COMPANY oF BOSTON, MASSACHUSETTS, A CORPORA TION OF MASSACHUSETTS.

ELECTROMAGNET.

Application filed April 23, 1925 Serial No. 25,305.

7 Y object to provide the electromagnet with an tion will be pointed outin the claims armature which will respond to electric currents o't varying or different strengths. To

this end, the electromagnet is provided with an armature having members capable of forming an air gap between them and preferably arranged so that the width of the air gap may be varied by the adjustment or one armaturemember with relation to the other and thereby increase or decrease the pull or attraction of the electromagnet upon the armature and thus adjust the electromagnet to meet variations in conditions of use, as will be described.

The invention is especially applicable to electromagnets employed for controlling the operationof other apparatus, such, for instance, as electric circuitcontrollers, which it is desired should respond to a given strength of current under certain conditions of use. v j j These and other features of this invenat the end of this specification Fig. 1 represents in elevation and section one form of electromagnet embodying this invention, the members of the armature bemg shown in contact, and

' Fig.2, a like view with themembers of the armatureseparated by an air gap.

In the present instance, theinvention is shown as embodied in that form of electromagnet known as a solenoid, which is provided with an armature in the form of a core.

The solenoid of'a coil or winding rt located in a casing or shell I) having a head 0 throughwhicb is extended a rod (Z having a reduced threaded portion 10.- The rod (Z has mounted upon it a core or armature comprising a plurality of members, herein shown as two m-nunr her and marked 12. 13.1 The: member 12 is mounted on the threaded portion 10 and bears against a shoulder 14 and is forced against said shoulder by a nut 15 on the I bo e vh eh e gag s the threa d. p n

may be of any desired con struction and is herein shown as composed 10 and is capable of being adjusted on said threaded portion 10 toward and from the fixed member 12. The member 13 is provided at its upper end with a socket 16 for the reception of the nut '15 when the member 13 is in contact with the member 12 as representedin Fig. 1. The member 13 is also provided. .at its lower end'with a socket17 traction or pull upon the armature and responds to a predetermined strength of current flowing through the magnet to elfect thedesired movement of the armature.

l Vhenhowever the armature member 13 is moved away from the member 12 so as to provide an air gap 20 between said members, as represented in Fig. 2, the attractive force or pull'upon the armature is decreased, so that it will require a greater strength otcurrentto eftect'the desired movement of the armature. j r By adjusting the member 13 into different positions with relation to the member 12, the air gap 20 may be made of different widths 01" sizes to enable .the armature to respond to difi'erent'strengths' of current. An electromagnet of this characteris ospecially useful in connection with apparatus represented by a togglecomprising the mem bers 30, 31. whose center pin 32 isconnected by a link 33 with the rod (i, so that when the electromagnet'is energized and its armature or core is attracted and moved upwardly for a predetermined distance, the toggle is moved from its straightened or closed position into its inclined or broken position, Fig.1 1, with attendant operation of the apparatus represented by the toggle.

In the present instance, the upward movement of the armature or'core is limited by the head owith which the fixed member 12 is brought in contact; Y r r i As herein shown, the rod d is'provided at its upper end with a head 34 having an opening 35 through which is extended a pin 36 which connects the-lower end of the link 33-with a forked lever 37 pivoted at 38 to a lu 39 on the ma net casin or shell I);

D D b 'l he pin' 36 co opeliatesw-ith the upper wall O oh the head when. the. core or armature. is moved downward and with the lower wall etl of said head when said core is moved upwardly. i t

To illustrate the usefulness of an electromagnet, such as herein shown and described, letit be assumed that" the electromagnet is designed to function at two amperes,and' that when connected with the apparatus-represented by the toggle 30, 31, the conditions. are changed so tliatl'a greater or less'current" is required to'operat'e the electromagnet and the apparatus con-trolled thereby,

Assume. for instance that when the armar ture is adjusted soas to be provided with any air gapQQ of one-lialf inch, it will respond to a current of two amperes and operate the apparatus controlled by it in the proper manner. 7

Assume also that a condition arises in the apparatus controlled. by the electromagnet and represented by the toggle 30, 31, whereby a current. ofgreater or higher strength, as for instance two and two-tenths (2.2) a-mperes is required. to operate the electromagnet. and the. apparatus controlled by it. Under these latter conditions, the operator adjusts, the armature member 13' so as to increase the air gapQOand thereby decrease the pull of the electromagnet" upon the, armature and allow the current flowing through the electromagnet to build up to two and two-tenths: (2.2) amperes and thus enable the apparatus controlled by the electromagnet to be operated the same as it is operated when the. conditions of the apparatus are such that it is operated with a current of two amperes It on the other hand, the conditions of use are' such that the apparatus is operated by a: current of. less'strength, as for in stance, one and eight-tenths (118) amperes, the armaturemember 13 is adjusted so. as to decrease the air gap 20 and thereby increase the pull of the magnet and cause the apparatus controlled by the eleotromagnet to be operated as it isdesigned to operate with the normal air gap represented by the two ampere current. 7

It will. thus be seen that by lengthening or shortening. the air gap between the members of the armature, the apparatus controlled .by the. electromagnet is caused to operate in the proper manner.

It will. further be observed that by'widening-or increasing the air gap, the pull or attraction of theelectromagnet upon the art e isw akened or dimini h d, and y diminishing or closing the air gap, the pull or attraction ofthe electromagnet is increased.

]?n the present instance, the invention is shown in an electromagnet of the solenoid type, but itis not desired to limit the invention. in this; respect, as: it. is equally applicable to. the. MIIMLlEIIIZBS-JOll-Z other: types of electromagnetsz...

WVhat' I claim is:

1. A solenoid provided with a rod having a 'threaded portion of smaller diameter formingfa. shoulder, a core member on. said threaded portion, anut to secure said core member in'fixed position on'said rod, a second lcore member in threaded. engagement with the threaded portion ot" said rod to move as, one piece; with the fixed core-member when said solenoid is energized and adjustable thereon toward and from said fixedcore member to form, air gaps ofdiflerent sizes, and a nut to retain said second core member in itsadjusted position.

2. A solenoid provided with a rod, a core member mounted thereon andihaving'a fixed relation thereto, and a second cor-e member mounted .on saidrod. to move longitudinally thereon toward and fro msaid; fi'xed'memone of said members tobe moved vary'the size of said: air gapand to maintain-said air gap and perm-it both members to hemmed as one piece Withthe gap between them when said elect-rom-agnet is energized.

5. An electroma-gnet provided with an armature having members separated by an air gap and connected together to maintain the air gap and cause the armature to. be

moved as one piece in resprmse'to a current of. given strength flowing through the electromagnet'.

6.'An 'electromagnet having an armature provided with members adjustable with relation to each other toform between them air gaps'o-f different sizes and secured in their adjusted position in fixed relation to maintain 'theselected gap. While the armature i's'bei-ng moved and cause the. armature to be moved as one piece in response to a current of given strength flowing through the elect-romagnet.

7,. An eIect-romagnet provided with an armature having memberscapable of forming an air gap between them, a. support for said members on which one of said memtween said members and cause them to be moved as one piece in response to a current of given value flowing through the electro- 10' magnet.

In testimony Whereofl I havesignedmy name to this specification.' H

ALF En ANDERSON. 

